Passive cooling

The case is made from a big 450x250 heat-sink from an old UPS. I cut it in two with a circular saw and used the two pieces for the sides. I had some MSB frame extrusions from a project that never got off the ground, and used them to form the front and rear.

The smoked acrylic panel for the front was cut from an old printer hood. I bought the large 20 character, 2 line Vacuum Fluorescent display for a fiver from a radio rally.

I striped down the micro ATX PSU, removed the heat-sinks and replaced them with a couple of machined heat shunts; to move the heat to the left case heat-sink.

The CPU and North Bridge chips are cooled by two tandem copper blocks screwed to the right case heat-sink. The copper came from metal reclamation yard for scrap cost £5

The copper blocks on the north-bridge and CPU work really well (CPU rarely gets over 60°C, about 35°C over ambient) I might extend the copper over the south-bridge chip, although the current 486 heat sink seems to do the job fairly well. The PSU runs at around 45°C which is ok, except it tends to heat the Nebula card, which sits just above it in the case, so I’ve had to fit a heat shunt on the back of the card to take a bit of heat in to the back panel ( I like things to be just warm to the touch )

The Nebula Infrared remote interface is decanted onto a piece of Vero board and mounted above the Wexim JM100 IrDA interface on the right hand side of the case.

To avoid making a hole in the front panel, I used a Quantum research QT113 touch switch circuit, mounted on the left side of the case.

I couldn’t make the old CD player case quiet enough so, I decided to take a completely new approach to the case design. This one would be cooled passively without any noisy fans.